Supervisor: Mr. Hai Vortman

The ultimate goal

• Creating a wireless sensor network using Bluetooth technology.

The project Goals

Developing software for the sensor and for the server.

Developing a work area in order to testing various wireless network protocol such as Gradient Algorithm PIF,CT3 and CT2.

Testing our WSN using several computers and comparing reliability with the expectation.

Suggesting solutions to save energy using this kind of already very low power sensor consumers.

Why our project is very interesting

• Practical • Very low effort for usage in real system

simulation • Can be used from labs that would like to test

any event detection system.• Can be easily developed for other devices

such as (mobile)

Overview• The Bluetooth Special Interest Group was

founded in September 1998.

• The SIG has more than 11,000 member companies.

• Last decade:1.5 billion Bluetooth enabled devices have been shipped.“The first ten years of Bluetooth development has been amazing to watch,” said Michael Foley, Ph.D., executive director, the Bluetooth SIG. “From prototypes in 1998 to more than 1.5 billion devices on the market today, no other consumer technology has grown as fast in such a short period of time.”

Bluetooth Stack

Bluetooth Piconet and Scatternet

Bluetooth + and -

• Advantages:– Power ! – Commonness : more than 1.5 billion Bluetooth devices.– Low cost.

• Disadvantages:– Little bandwidth– Low Security– The network is constructed from several piconets. Each

piconets compound from master & up to 7 slaves.

Class 1100mW100m

Class 22.5mW10m

Class 31 mW1m

BT vs. Wi-Fi

• Wi-Fi differs from Bluetooth in that it provides higher throughput and covers greater distances, but requires more expensive hardware and may present higher power consumption.

• Wi-Fi enables a faster connection, better range from the base station, and better security than Bluetooth although….

WSN Technology• A wireless sensor network (WSN) is a computer

network consisting of distributed autonomous devices using sensors to detect events and spread data.

• There are several main obstacles that need to be overcome before when designing a wireless sensor network:

1. Energy.

2. Computation

3. Communication

Wireless Sensors Network Tradeoff

• Usually the main trade-off that are taken under consideration when designing a wireless sensor networks is between energy and communication overhead saving in every routing solution.

WSN – our implementation

• Basic constrains:1.A unique Base Station2.Can be any number of sensors3.Message sent only one way4.Maximum sons (7) - (Hardware constrain)

State machine for BS

State machine for sensor

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The SystemSystem Requirements (briefly )

The Sensor entity (henceforth called the system) is a software application responsible to implement a pre-defined state machine in order to enable event identification and reliable communication with other sensors entities.

Such a system could be very useful and helpful in buildings security and administration, army systems, event propagation systems etc…

System Context

The system will run on every machine that has the following requirements:512K minimum of total memory availableBluetooth wireless network connectionCompliant implementation of the J2ME Connected

Limited Device Configuration

The system shall provide a GUI for controlling and configuring each sensor.

Functional Requirements

Communication

The application should be able to gathering data on the environment and decide his responsibilities.

The application should be able to receive information from the slaves and transfer to the master/server and vice versa.

The application should check for new potential connection from time to time.

Given an event the application should transmit it to his master.

…. Continue… (Functional Requirements)

Event Detection

The software should be designed independently from the kind of event.

…. Continue… (Functional Requirements)

Environment changes support

The system should be able (considering that is possible) to rebuild itself in case of environment “little” changes:

Example: some sensors stop working.

Note: The system is not design for support a moveable network.

Software component

Demonstration..…

Disconnection case

Two different approach1.The device is not always connected. That

means that there is a check from time to time + a transmission that can reveal a failure(Power saving)

2.The device is always connected so that the failure is in reveal in real time.(Better for demonstration and less time to rebuild the network)

Future possible implementation

• Implement other kind of WSN algorithms: PI (Routing via Broadcast),PIF

• Implementation of Connectivity Test algorithms: CT2, CT3

• System improvement1. Usage of more than one BS 2. Ranking system improvement

• Mobile adaption

Thank you